The flameless heat source only gets hot when it's warm outside. I ate MRE's when I was stationed in Germany. Germany is cold when we went to the field (didn't matter what month it was, it snowed). Best case was that it might get slightly warmer than frozen.

The cheese will make you regular. You can almost set a clock to it.

I miss the Ham Slice. It came with noodles and the cheese, you mix em all up and you've got a pretty decent cassarole.